Appliance for boring metals or other hard substances.



H. AUSTIN.

APRLIANQE FOR BORING METALS OR OTHER HARD SUBSTANCES. APPHCATIONJILED NOV. 21. 1915.

1,226, 1 64:. Patented May 15, 1917.

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y E srrs ran HERBERT AUSTIN, 0F BROMSGROVE, ENGLAND.

APPLIANCE FOR BORIN G METALS OR OTHER HARD SUBSTANCES.

Specification of Letters Patent.

Application filed November 21, 1916. Serial No. 132,647.

This inventionhas for its object an im proved appliance for boring in metal or other hard substance a cavity which is re quired to vary in diameter, the more immediate purpose of the invention being for boring shells which are parallel inside for some distance and gradually curve to a smaller diameter towardthe front end.

An appliance constructed according to this invention has a barwhich directly carries the cutter, mounted, eccentrically of the axis of the interior of the article to be bored, in a holder whiehis adapted to travel endwise of the machine with which the appliance is used, and the bar is capable of a turning movement in relation to the holder. hen the applianceis boring a parallel portion of a cavity or chamber, the bar is prevented fromturning in relation to the holder, and the cutting edge of the cutter is consequently maintained at a constant distanoe from the axisof thecavity. In consequence of the axis of the bar being eccentric to the axis of the cavity, if the bar is turned in relation to the holder, the cutter is moved farther from or nearer to the axis of the cavity and bores to an enlarged or reduced diameter. A groove isformed in the surface of the bar andfollows a eourse within such surface which adapts it to the special turning within the holder, but is prevented work required. A key which may be constituted as a roller engages with this groove and. except as hereinafter mentioned. is (or its axis is) stationary. and consequentlv as the bar moves forward it is prevented from turning. if the portion of the groove within which at the time the key engages is parallel Patented May 15, 1917.

to the key, and the groove is formed to run in acurved or slanting direction partially around the bar, and, on the tool reaching the point where the bore of reducing or enlarging diameter commencesthe key is prevented from moving farther forward, with the result that the further movement forward of the bar, in relation to the key, causes the bar to turn.

In order that the invention may be clearly understood, I will now describe a convenient application of the same as applied, by way of example, to boring an explosive shell:-

Figure l is a longitudinal section through the shell and through a considerable portion of the boring appliance, the remainder of which is shown in side elevation.

Fig. 2 is a similar view to Fig. 1 but shows the boring appliance entirely in elevation.

Fig. 3 is a view of the inner face of the bracket hereinafter described.

Fig. 4 is a front end view of the boring appliance, the interior surface of the shell ducing diameter.

A is the shell which is being bored, B is a holder within which is fitted a cylindrical. bar C which carries at its-forward end the cutterD. The bar 0 is parallel'with the holder B, but its axis is eccentric with the axis of the shell. The bar is capable of of the hereto the portion of gradually refrom moving endwise in relation to the holder by the engagement of a pin 7) of the holder with an annular groove 7) which is turned in the rear end of the bar, and the backward thrust of the bar is taken by the pressure of a hardened steel conical. surface 0 thereof against a corresponding surface of the holder. A roller or key c is carried by or formed with the forward end of a checlo rod E which is slidable within a longitudinal groove 72 of the holder B and along the surface of the bar C. and this roller or key enters a grooveo which is formed within the surface of the bar C and runs partially therearound and at thesame time endwisc thereof, and on the rear end of this rod are a pair of lock nuts 0 which are shown, in Fig. 1, as against the rear faceof a bracket F which is fixed to the bed (not shown) of the machine.

The rear end of the holder B is fixed within a headstock, or the like (not shown), which is slidable along the machine bed and is automatically moved therealong, such as by a leading-screw or other device, and the forward end of the holder enters within the parallel portion of the cavity which is being bored.

To commence the parallel out, the headstockis moved back such distance in relation to theshell that the cutter D can commence the out, and the roller or key 6 is then within the forward end of the groove 0, the bar having been .turned to such a degree that the cutter is then therequired distance from the axis of the shell'for boring the parallel portion of the cavity. Owing to the portion of the cavity within which the roller or key a is then situated running mainly in an endwise direction, it prevents the bar C turning within the holder B and the check-rod E is carried forward with the holder and the cutter is maintained at a constant distance from the axis of the shell. When, however, the cutter has advanced to the point where the conoidal boring is to commence, the locknuts e are against the bracket F and the check-rod E cannot be carried farther forward. vance of the holder then causes the groove 0 to travel forward in relation to the roller or key e, with the result that the bar C turns and gradually brings the tool D nearer to the axis of the shell. The groove 0 is, of course, shaped endwise to insure that the turning of the bar C will move the cutter nearer to the axis of the shell in such manner as will insure that, as the toolholder advances, the conoidal portion of the interior of the shell will be bored to the shape required.

G is a spring which is fixed at one end to the bracket F and at its free end bears against the rear end of the check-rod E. This spring will prevent the check-rod from moving substantially backward while the boring appliance is moved backward after boring a cavity, and therefore as the appliance is moved back, the'bar will turn in relation to the holder B until the forward end of the groove 0 has come against the roller I or key c, after which the spring G is turned sidewise clear of the check-rod E and the lock-nuts e and allows the boring appliance to be moved farther back, namely,'into the position for commencing to bore the next shell.

His a tube which surrounds the check-rod E between the holder'B and the lock-nuts 6. When the appliance is moved back clear of The farther adthe shell, a bush 6 which is fixed in the back end of the holder B and through which the rod E is slidable, comesagainst the forward end of the tube H, whereby this tube gages the distance between the holder and the locknuts 6 and insures that, when the boring cut commences, the roller or key 6 will be in proper position in relation to the bar C. The check-rod E is shown as formed in two portions, of which the forward portion 0 is of a'rectangular shape to slide within the groove 6 except that its surface which is slidable along the bar C is slightly concave to suit the convexity of the surface of thebar, and of which the rear portion e is round and is screwed into a socket e which is formed onthe rear end of the portion 0?. A grub-screw e, or the like, is used to prevent the accidental unscrewing of the portion 6 within the socket c. The rod E is put into place from the back end of. the holder B, and is first pushed forward until. the roller or key 0 is sufliciently forward of the forward end of the holder to allow the groove 0 of the bar C to be engaged there with as the bar is being put'into place, and, when this engagement has been effected, the bar C and the rod E are moved into their required positions. With a view to avoiding unnecessary length in the appliance, the cylindrical hole 6 along with the socket e r is slidable, has one side If thereof carried forward beyond the inner end of the opening in the holder which is to receive the bar C, whereby the socket 6* may be moved somewhat into such opening in pushing the rod endwise prior to engagingthe groove 0 with the roller or key 0. b is a key which is fixed at the underside of the rear end of the holder'B, for the purpose of engaging with a keyway of the headstock or the like which carries the holder.

Three anti-friction rollers K are carried by the forward end of the holder B and just touch the interior surface of the portion of the shell which is bored parallel, thereby maintaining the holder from vibrating while the boring is taking place. Sheet metal or other suitable shields 7c are carried by the holder B to prevent swarf getting in be tween the bored surface and the side roller toward which the underside of the article whichis being bored turns upward and between such surface and the bottom roller; and to prevent swarf getting in between the bar C and the holder B, the portion of the bar C which projects through the front of the holder is surrounded by a cap M within a groove of which is inserted suitable packing N. The cap is conveniently formed of two plates m, and the pacln'ng is compressed within a groove which is formed partially in the inner edge of one plate and partially in the inner edge of the other plate, the plates being held against the end of the holder B,

and tightened against one another, by means of the pins which secure the rollers K in place and around which they revolve. P indicates tubing for thepurposeof lubrication.

If a cavity to be bored is of a difierent character to that shown in the drawings, the formation of the groove in the bar will, of course, be modified accordingly; and in many cases it will not be required that the key shall travel with the bar during any por tion of a cutting operation. The character of the cavities which it may be required to bore may vary indefinitely and the details of construction will vary correspondingly, as will be obvious.

Having fully described my invention, what I claim and desire to secure by Letters Patent, is

1. A boring appliance for boring a cavity of varying diameter in metal or other hard substance, comprising an endwise traversable substantially cylindrical holder provided. in 3' ts forward portion with a longitudinal tubular socket parallel with and eccentric to the axis of: the cavity to be bored, a cutter bar turnable in said socket, projecting in front of said holder and carrying a cutter in its projecting portion, and means for antomatically turning said cutter bar continuously Within said socket while a cavity is being bored to a continually varying diameter to shift said cutter toward or from the axis of the cavity and change thediameter of traverse of said cutter.

2. The combination, in an appliance for boring in metal or other hard substance a length of cavity which is required to vary in diameter, of a holder which. travels endwise, a bar carried by said holder eccentrically of the cavity to be bored and provided with a groove within said bar, a cutter carried by said bar, and a key which is carried by said holder and engages with said groove and is stationary in relation to the holder, and said groove being shaped to insure that its interaction with the key will turn the bar as required for variations in the diameter of said length of cavity.

3. The combination, in an appliance for boring metal or other hard substance in which a cavity to be bored is parallel for a portion of its length and varies in diameter for another portion of its length, of a holder which travels endwise, bar carried by said holder eccentrically of the cavity to be bored and provided with a groove within such bar, a cutter carried by said bar, a rod which is slidable in relation to the holder, a key which is carried by said rod and engages with said groove, said rod and key traveling with said holder while the cutter is boring said parallel portion of the cavity, but arrested from traveling forward at a point where it is'required that the bar shall commence to turnto control the position of the cutter in relation to the axis of the cavity for the purpose of further boring the cavity as required, said groove being of such shape as to insure that its interaction with the key, when the key is held stationary in relation to the holder, will. turn the bar as required for variations in the diameter of the cavity.

4. The combination, in an appliance for boring metal or other hard substance in which a cavity to be bored is parallel for a POilLlOl'] of its length and varies in diameter for another portion of its length, of a holder which travels endwise, a bar carried by said holder eccentrically of the cavity to be bored, a cutter carried by said bar, means by which said bar may be turned in relation to said holder, and anti triction rollers carried by said holder which just touch the parallelbored surface of the cavity and steady the forward end of the holder while the boring operation is taking place.

5. The combination, in an. appliance for boring metal or other hard substance in which a cavity to be bored is parallel for a portion of its length and varies in diameter for another portion of its len th, of a holder which travels endwise, a bar carried by said holder eccentrically of the cavity to be bored and provided with a groove within such bar, a cutter carried by said bar, a rod which is slidable in relation to the holder, a key which is carried by said rod and engages with said groove, said rod and key traveling with said holder while the cutter is boring said parallel portion of the cavity. a shoulder of said rod which, when said holder has reached the point of its travel when the bore of varying diameter is to commence, is against a fixed abutment and arrests the travel of said rod, and said. groove being of such shape as to insure that its interaction with the key, when. the movement of the key has been arrested, will turn the bar as required for variations in the diameter of the cavity.

6. The combination, in an appliance for boring metal or other hard substance in which a cavity to be bored is parallel for a portion of its length andv varies in diameter for another portion of its length, of a holder which travels endwise, a bar carried. by said holder eccentrically of the cavity to be bored and provided with a groove within such bar, a cutter carried by said bar, a rod which is slidable in relation to the holder, a key which is carried by said. rod and engages with said groove, said rod and key traveling with said holder while the cutter is boring said parallel portion of the cavity, a shoulder of said rod which, when said holder has reached. the point of its travel when the bore of varying diameter is to commence, is against a fixed abutment and arrests the travel of said rod, said groove moved clear of the rod and allow the rocl being of such shape as to insure that its into move back, with the holder and bar.

teraction with the key, when the movement In witness whereof I have hereunto signed of the key has been arrested, will turn the my name this 8th clay of November, 1916, in

,5 bar as 'requirecl' for variations in the cliamethe presence of two subscribing witnesses. 15

ter of the cavity, and amovable abutment which may be brought behind the rod when HERBERT AUSTIN. in its forward position, to allow said holder Witnesses: I and bar to be moved back in relation to the ERNEST PARKER,

10 rod, for any required distance, and then be KATHLEEN M. THOMPSON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G. V i 

